Critical care Flashcards
Which of the following statements best summarizes the findings and clinical implications of comparing two analyzers (Beckman Coulter AU480 Chemistry analyzer (PBMA) and a Nova Biomedical
Stat Profile (WBGA)) in determining electrolyte concentrations and diagnosing acid-base disorders in sick horses using the simplified strong ion difference (sSID) approach?
A) The study found perfect agreement between the two analyzers in measuring Na+ and Cl− concentrations, which resulted in consistent sSID calculations and diagnoses of acid-base disorders in sick horses.
B) The study revealed significant differences between the two analyzers in measuring Na+ and Cl− concentrations, leading to discrepancies in the calculation of the strong ion difference (SID4) and unmeasured strong ions (USI), resulting in poor agreement in diagnosing acid-base disorders in sick horses.
C) The study found that time between sample collection and analysis was the only factor influencing the differences in SID4 calculations and acid-base disorder diagnosis in horses.
D) The study concluded that the variability in total solids (TS) and total protein (TP) concentrations measured by the analyzers had no impact on sSID calculations or the diagnosis of acid-base disorders in horses.
B.Correct: This statement accurately summarizes the key findings of the study. Significant differences were observed between the two analyzers, especially in Na+ and Cl− measurements, leading to variability in SID4 and USI values, which affected the diagnosis of acid-base disorders.
A: incorrect: The study actually found significant differences between the analyzers in measuring Na+ and Cl− concentrations, not perfect agreement. These differences affected the sSID calculations and the diagnosis of acid-base disorders.
C. Incorrect: While time between sample collection and analysis did play a role, it was not the only factor. The type of sample (whole blood vs. plasma) and differences in measurement methodologies also contributed to the discrepancies between the analyzers.
D. Incorrect: The study found that differences in TS and TP measurements using different methodologies affected the calculation of the total weak acid concentration (Atot), which is one of the factors influencing the sSID model. This variability did impact the diagnosis of acid-base disorders.
Agreement of 2 electrolyte analyzers for identifying electrolyte and acid-base disorders in sick horses. 2020 JVIM
Which of the following best summarizes the key findings of the study on fluid flow rates through different equine catheters?
A) Fluid flow rates were primarily influenced by the viscosity of the fluid, and using a 14-gauge catheter provided the fastest flow rate at any height.
B) The fastest fluid flow rates were achieved using a 10-gauge catheter at a height of 200 cm, with flow rates increasing by 25-28% when the height of the fluid bag was increased from 150 cm to 200 cm.
C) Increasing the height of the fluid bag had no significant effect on fluid flow rates through different catheter types, and identical catheters showed poor agreement in flow rate consistency.
D) Fluid flow rates were highest with smaller-bore catheters and were unaffected by the height of the fluid bag or catheter type.
Correct Answer:
B) The fastest fluid flow rates were achieved using a 10-gauge catheter at a height of 200 cm, with flow rates increasing by 25-28% when the height of the fluid bag was increased from 150 cm to 200 cm.
Justification for incorrect answers:
A) is incorrect because the study found that the 10-gauge catheter, not the 14-gauge, had the fastest flow rates, and viscosity differences of fluids were noted as a limitation but not the primary factor influencing results.
C) is incorrect because increasing the height of the fluid bag significantly impacted flow rates, and there was excellent agreement between identical catheters.
D) is incorrect because wider-bore catheters, not smaller ones, provided the fastest flow rates, and the height of the fluid bag had a clear influence on flow rates.
In vitro flow rates through five different catheters intended for
intravenous use in horses at two different heights
S. Lord†,* , J. Duncan†, M. Gozalo-Marcilla† and K. Woodhouse‡ EVE 2022
Which of the following accurately describes the results of the study investigating the effects of ascorbic acid (AA) and hydrocortisone (HC) on horses subjected to LPS-induced endotoxemia?
A) The administration of AA and HC resulted in a significant reduction in pro-inflammatory cytokine gene expression, with both treatments drastically lowering neutrophil counts at 6 and 12 hours after LPS infusion.
B) Administration of AA led to a decrease in serum cortisol concentrations, while HC had no effect on cortisol levels, suggesting that neither treatment improved the horses’ response to LPS infusion.
C) The combination of AA and HC resulted in a significant improvement in clinical signs, decreased plasma SAA concentrations, and completely prevented the onset of CIRCI in the horses.
D) Administration of AA and HC did not significantly affect clinical signs or pro-inflammatory cytokine production, but AA led to higher neutrophil counts at 6 hours post-LPS infusion, and HC increased neutrophil counts at 12 hours. Serum cortisol levels increased post-LPS infusion, with no effect from treatment.
Answer D.
A) Incorrect: The study found no effect of AA or HC on pro-inflammatory cytokine gene expression or clinical signs. Additionally, AA and HC increased neutrophil counts post-LPS infusion rather than lowering them.
B) Incorrect: AA did not cause a decrease in cortisol levels, and there was no significant effect of any treatment on cortisol levels. Cortisol levels increased after LPS infusion, but this was not due to treatment.
C) Incorrect: The study found no significant improvement in clinical signs or plasma SAA concentrations with AA or HC administration, and CIRCI was still observed, indicated by a blunted cortisol response to ACTH.
D) Correct: This accurately reflects the study results. Neither AA nor HC significantly affected clinical signs or cytokine production, but AA increased neutrophil counts at 6 hours post-LPS, and HC increased neutrophil counts at 12 hours. Additionally, cortisol levels increased post-LPS infusion without a treatment effect.
2020 Anderson 2020 Effects of administration of ascorbic acid and low‐dose hydrocortisone after infusion of sublethal doses
How to calculate the amount of fluids to be given to a dehydrated horse ?
After obtaining an estimate of dehydration, the clinician can calculate the amount of fluids to be given as follows:
Volume (L) = Body Weight (kg) × % Dehydrated
You receive a 500 kg horse in emergency with profuse diarrhea, a CRT of 4 seconds, a heart rate of 80 bpm and an Ht/ST of 50/80. Lactatatemia : 6 mmol/L
How many liters of fluid are needed?
What causes hyperlactatemia?
Estimated dehydration of 10%. 50 L are needed
Type A lactic acidosis → increases in blood lactate concentration in the horse are most often the result of inadequate delivery of oxygen to peripheral tissues resulting from hypovolemia, hypoxemia, anemia or decreased perfusion pressure.
Which fluid should be used to perfuse a horse suffering from HYPP?
Renal failure ?
Hepatic failure ?
Physiologic saline (0.9% isotonic) might be preferable in conditions in which potassium restriction is indicated (e.g., hyperkalemic states, such as hyperkalemic periodic paralysis, uroperitoneum, renal failure) because balanced electrolyte solution all contain some potassium.
Lactate in lactated Ringer’s solution (LRS) requires hepatic metabolism; thus, LRS may not be an ideal choice in horses with liver dysfunction.
What precautions should be taken before administering bicarbonates to a horse suffering from metabolic acidosis?
Horses receiving bicarbonate therapy should have their respiratory function assessed because carbon dioxide (CO2) generated from carbonic anhydrase activity requires normal alveolar ventilation for effective CO2 removal. Respiratory compromise will result in worsening of acidemia caused by mixed metabolic and respiratory acidosis.
At what pH is bicarbonate supplementation necessary? At what supplementation rate?
For horses with a pH ≤7.2 caused by metabolic derangements (nonrespiratory) following shock crystalloid dosing (80 mL/kg in 1 h), isotonic bicarbonate (1.3%) therapy is indicated.
First, administer 50% of the bicarbonate deficit rapidly over 1 to 2 hours followed by the remaining 50% over 12 to 24 hours.
Deficit = BW (kg) × 0.3 × ([Bica]desired − [Bica]measured)
Note that parenteral bicarbonate solutions are incompatible with calcium-containing solutions (like Ringer Lactate).
What are the indications for using colloids?
Colloids may be indicated in patients with hypoproteinemia, severe blood loss, or those in need of clotting factors or immunoglobulins.
What are the indications for the use of hypertonic fluids?
Contraindications ?
Most clinicians select a polyionic isotonic crystalloid fluid (e.g., LRS or Plasma-Lyte A) administered alone, or in combination with hypertonic saline in the presence of clinical shock symptoms.
The use of hypertonic saline should be cautiously considered or avoided in cases of uncontrolled hemorrhage or where marked interstitial dehydration is likely. However, it has demonstrated a more rapid return of normal heart rate and urination in endurance horses requiring IV fluid support compared with normal saline.
What are the main causes of hyperlactatemia (2 types) ?
L-Lactate is the terminal product of anaerobic glycolysis.
Increases in blood lactate concentration in the horse are most often type A lactic acidosis, due to inadequate delivery of oxygen to peripheral tissue, resulting from :
- hypovolemia,
- hypoxemia,
- anemia,
- decreased perfusion pressure.
Type B lactic acidosis include abnormal tissue utilization of oxygen, including mitochondrial dysfunction, or abnormal clearance of lactate.
What is the clinical significance of persistent hyperlactatemia in situations of appropriate volume restoration?
In situations of appropriate volume restoration in which lactate concentration remains increased, unresolved inflammatory stimulus or uncontrolled sepsis should be considered.
When is oxygen supplementation indicated ?
Oxygen supplementation is indicated when the Pao2 ≦ 60 mmHg or Sao2 < 90%.
What are the complications associated with parenteral nutrition ?
Complications associated with PN administration include hyperglycemia, hyperlipidemia, hypokalemia, hypophosphatemia, hypomagnesemia, and thrombophlebitis.
Hypokalemia can result from decreased intake of food and the delivery of a high concentration of dextrose causing pancreatic insulin release. Thus, potassium should be supplemented in horses receiving PN.
What are the contraindications of PN containing lipids ?
Parenteral formulations containing lipids should be avoided in horses with hyperlipidemia, hyperlipemia, or severe liver disease and used with caution in horses with severe endotoxemia or SIRS.
